The present invention relates to a device for adjusting the timing of a seal cutter, a sealer or a cutter in preparation for starting the operation of a packaging machine.
There are known packaging machines for wrapping articles with a web of patterned wrapping paper as it is continuously formed into a sleeve, sealing the ends of a sleeve enclosure with an article therein, and finally cutting off the sleeve enclosure at the sealed ends. With such packaging machines, it is necessary to detect registration marks printed at the pitch of the patterns on the wrapping paper and drive a rotary seal cutter in timed relation to passage of the registration marks in order to produce packages aligned with patterns printed on the wrapping paper.
When different articles are to be packaged or a different web of patterned wrapping paper is to be used, it has been customary practice for the operator to make adjustments in preparation for the operation of the packaging machine. Such preparatory adjustments include readjustment of the cutting pitch of the rotary seal cutter, that is, the interval at which the wrapping paper is to be cut off, initial adjustment of the angle of the rotary seal cutter with respect to an attachment on a feed conveyor, and adjustment of the timing at which to detect registration marks on the wrapping paper with the rotary seal cutter serving as a reference. These preparatory adjustments have been effected manually by the operator, and hence are low in efficiency and require much skill on the part of the operator. Where the adjustment made is subjected to an error, or something is left to be adjusted, many articles are wrapped improperly.
In case articles of a different thickness are to be wrapped by wrapping paper having registration marks spaced at equal intervals, it is necessary to change the cutting pitch of the rotary seal cutter based on the registration mark interval. However, the thickness of the articles cannot be entered as a setting into the conventional device for adjusting the timing of the seal cutter. This fails to make exact ajustment to meet the change in the thickness of the articles. Therefore, it has not been possible to seal and cut the wrapping paper at correct positions when the thickness of articles is varied.